arrays within query parameters

[twifty]

The API states that some of the query parameters can be duplicated. for example the 'extrahosts' and 't' parameters of ImageBuild.

I see this library makes use of querystrings, and correctly converts objects to JSON strings. But, it doesn't handle arrays. So, for example, given an object like:

{
   extrahosts: [
     "somehost:162.242.195.82",
     "otherhost:50.31.209.229",
   ]
}

querystrings will covert to 'extrahosts[0]=somehost:162.242.195.82&extrahosts[1]=otherhost:50.31.209.229' (escaped of course).

docker-py uses the requests package which simply repeats the name and is consistent with the API docs: 'extrahosts=somehost:162.242.195.82&extrahosts=otherhost:50.31.209.229' .

While the array notation may work on some systems, it all depends on the binary the daemon uses. It may very well break on some OS's or daemon versions.

[ghost]

@twifty arrays aren't being querystringify'd properly due to buildQuerystring (https://github.com/apocas/docker-modem/blob/master/lib/modem.js#L350). Arrays are being stringify'd before being passed to querystring.

/cc @apocas

[apocas]

Interesting, will check this one.

[apocas]

I can't replicated this, there's even a test for this.

https://github.com/apocas/docker-modem/blob/master/test/modem_test.js#L109

INPUT:

 var opts = {
      "limit": 12,
      "filters": {
        "label": ["staging", "env=green"]
      },
      "t": ["repo:latest", "repo:1.0.0"]
    };

OUTPUT:
limit=12&filters={"label":["staging","env=green"]}&t=repo:latest&t=repo:1.0.0

The array "t" was properly converted.

[ghost]

@apocas the test case works because of key !== 't'

docker-modem/lib/modem.js

Line 351 in 01cac74

clone[key] = (opts[key] && typeof opts[key] === 'object' && key !== 't') ?

[apocas]

Missed that. Can't remember why that was done.
I suspect that endpoints didn't behave the same way, regarding input.

Will check if removing the stringify doesn't break anything.

[apocas]

Passes: https://github.com/apocas/dockerode/blob/master/test/docker.js#L648
Fails: https://github.com/apocas/dockerode/blob/master/test/docker.js#L658

So we can't just remove the stringify. Add that parameter as an exception?

[ghost]

@apocas looks like it was introduced with this commit: 8565c3f. Regarding my use case, as far as I remember it was related to passing an array of environment variables when creating/starting (not sure) a Docker container using dockerode. It was not working and debug'd down to this part of the code in docker-modem.

[apocas]

But we can't just remove this condition because the are endpoints expecting the data "stringifed". Like https://github.com/apocas/dockerode/blob/master/test/docker.js#L658

On the other hand there are parameters that are expected by Docker to be repeated like "t" in imageBuild. https://docs.docker.com/engine/api/v1.40/#operation/ImageBuild
"A name and optional tag to apply to the image in the name:tag format. If you omit the tag the default latest value is assumed. You can provide several t parameters."

If "extrahosts" is one of this cases we can add it to the exception list, like "t".
(Docker documentation does not detail this enough in this use case)

[roddc]

@apocas I tried to get multiple images, I need to pass names as array to query, but it doesn't work.
I think you need to check the opts[key] is Array or not

[lstocchi]

Same here, i was working with the getImages function from dockerode and i discovered the query string is not created as expected.
My object

{
names: ["name1", "name2"]
}

gets changed to

{
names: "[\"name1\", \"name2\"]"
}

in the cloned object and the querystring created by it it's incorrect.
/images/get?names=%5B%22name1%22%2C%22name2%22%5D
instead of
/images/get?names=name1&names=name2

Happy to help if you want!!